The present invention relates to a process for producing bread. The present invention also relates to a bread dough which can be used in the process according to the present invention. Further, the present invention relates to a bread improver composition which can be used in the process for producing bread according to the present invention and to a bread with a long shelf-life.
During storage from the time of baking the bread to the time of consumption the softness of bread decreases and the organoleptic properties deteriorate so that the quality of the bread does not longer meet the standard requirements. This undesirable change in the quality of the bread is described by the term staling. The staling process is characterized by an increase in the firmness and a decrease in the elasticity of the crumb of the bread. Also the organoleptic properties of the crust rapidly diminish upon prolonged storage of the packaged bread at ambient conditions.
In order to obtain bread with a shelf life of 3-5 days and a bread quality which meets the standard requirements, it has been proposed to use emulsifiers in the manufacturing process, such as monoglycerides or calcium stearoyl lactylate, to improve dough strength and crumb softness and to remedy staling. If the emulsifiers are omitted, however, usually at best bread having an average shelf life of at most 3 days can be obtained. Moreover the quality of the bread without emulsifiers is rapidly deteriorating upon storage. It is advantageous, however, to delete the emulsifiers, since they are considered to be chemical additives by the public.
Therefore there is still a great need for a bread production process on commercial factory scale in which preferably no emulsifiers are used and yet leads to bread with a long shelf life and which bread also after long storage meets the standard quality requirements.
It has also been proposed to increase the levels of fat or shortening used in the manufacture of bread so as to achieve a longer shelf life, but the amount to be used to achieve appreciable benefits is rather high, which is unacceptable from a health point of view. Furthermore the use of thickening agents to increase the shelf life of commercially produced bread has been proposed, but this use leads to inferior organoleptic quality of the bread.
Finally it has been proposed to retard the staling of bread without adversely affecting the required organoleptic properties by adding enzymes or enzyme mixtures during the commercial bread production process. It has been reported that thus the organoleptic properties of the bread can be improved.
Thus, it has been proposed in EP-A-0 585 988 (Gist-Brocades NV) to use a mixture of lipase, hemicellulase and amylase, preferably in combination with shortening, to avoid the use of emulsifiers in the bread manufacture process. In the examples given in this patent, the obtained bread is stored for 3 days in polyethylene bags at room temperature. Nowhere in this patent a shelf life of longer than 3 days has been suggested or indicated however. Only changes in crumb firmness are indicated, but there is no indication or suggestion of the organoleptic and further physical properties of the bread after 3 days storage.
Furthermore it has been proposed in WO 99-53769 (Novonordisk AS) to use a combination of an anti-staling amylase (such as maltogenic alpha-amylase (Novamyl)) to reduce the rate of crumb firming during storage and a phospholipase to improve the softness in the first 24 hours after baking. After 2 days storage the firmness has already markedly increased. There is no suggestion or indication whether the use of the combination of the two enzymes leads to a shelf-life of the bread beyond 7 days.
There is still a need for a process on commercial industrial scale for producing bread having a relatively long shelf life of at least 7 days and satisfactory organoleptic and physical properties (such as a bread without unacceptable decreasing crumb elasticity, softness and/or freshness within a period of at least 7 days) and preferably without using added emulsifiers and added thickening agents or increasing the amount of conventional additives (such as fats and/or sugar), above the conventionally used levels in the commercial production of bread